Field of the Invention
The invention generally relates to saw blade chucks used for attaching saw blades to saws. More particularly, the invention relates to a quick release saw blade chuck which may be used with a saw having a blade connected between the free ends of a C-shaped or U-shaped member, such as, for example, a scroll saw or jigsaw. In addition, the invention relates to a scroll saw incorporating the quick release saw blade chuck.
Description of the Invention Background
In any saw using a saw blade having terminal ends, a device must be included for attachment of at least one end of the saw blade. Scroll saws and jigsaws, for example, typically include a two-armed, C-shaped or U-shaped member or yoke which reciprocates around a pivot point at the yoke's rear or center. A saw blade is connected between the free ends of the arms and cuts the workpiece through the yoke's reciprocating motion. In use, it is often necessary to detach one or both ends of the saw blade: worn or broken blades require replacement; one blade type may be replaced with another type for a specific application; or one end of the blade may be detached from the machine to pass the blade through a hole in the workpiece. As such, the design of the device which retains the saw blade becomes important.
In a scroll saw, the end of a saw blade is typically attached to the free end of the yoke by a saw blade chuck which exerts clamping force on the blade by tightening either a screw or a nut. FIG. 2 of U.S. Pat. No. 4,681,006, issued to Miller on Jul. 21, 1987, illustrates a device which clamps the end of the blade between the flat surface of a blade holder member, attached to the reciprocating arm, and a square nut threadedly attached to a threaded screw extending through a portion of the blade holder member. U.S. Pat. Nos. 2,099,321 and 1,964,651, issued to Tautz on Nov. 16, 1937, and Jun. 26, 1934, respectively, disclose a scroll saw blade chuck which retains the saw blade end through force exerted by tightening a thumbscrew against a wall of the chuck. FIGS. 9 and 10 of U.S. Pat. No. 1,877,705 issued on Sep. 13, 1932, to Tautz teach a scroll saw blade chuck including a horizontally extending socket head set screw threaded into the chuck body to place clamping pressure on jaws within the chuck.
In addition to requiring significant time to change or detach a blade, the aforementioned existing designs require either the use of tools or the exertion of significant force to securely clamp the blade within the chuck. Changing a blade can become frustrating where, for example, the threads of the chuck's set screw are clogged or otherwise impaired, thus making rotation difficult. Because the blade may need to be detached or replaced frequently, it is desirable to provide a saw blade chuck which may be quickly and easily opened and closed to reduce the time and effort necessary to detach or replace saw blades.